> hi, I'm new, here. I've been using "trigon" & "tetragon" > for a while, partly since everyone is familiar > with trigonometry, but I was wondering whether "triga" (etc.) > is the appropriate plural; > should GONS really be GA ??
No. I think the Greek plural would be "gonoi" (but am not sure).
However, although some Latin-derived words are still modified in the Latin way, it seems that nobody evr does the same thing with the Greek-derived ones, so it doesn't much matter.